The ultimate online
screen test & display diagnostics hub.

A screen test is a diagnostic tool used to check the health and performance of your display. Whether you are using a monitor, laptop, or mobile device, a screen test online helps you identify issues like dead pixels, backlight bleed, and color banding. By displaying specific colors and patterns, a screen test tool allows you to visually inspect your display for any hardware defects or calibration errors, ensuring you get the best possible image quality.

To test your screen online, simply use our browser-based screen test tool. Close any distracting windows, ensure your browser is in fullscreen mode, and use the navigation to select a specific test. You can cycle through solid colors to find dead pixels, check gradient images for color banding, and use dark slides for an OLED burn in test. Our display test runs entirely in your browser with no software installation required.

A dead pixel test involves displaying solid, bright colors across your entire screen to spot unlit or malfunctioning pixels. Using our screen test tool, launch the dead pixel test and enter fullscreen mode. Cycle through the pure red, green, blue, white, and black screens. Inspect your monitor closely; a dead pixel will typically appear as a tiny, permanently black dot that fails to light up on any color background.

A dead pixel is permanently off and appears as a tiny black square because it receives no power. A stuck pixel, on the other hand, receives power but is frozen in one state, usually appearing as a bright red, green, or blue dot on a dark background. While a dead pixel is generally permanent, a stuck pixel test and repair tool can sometimes fix a stuck pixel by rapidly flashing colors to unstick the liquid crystal.

To perform a backlight bleed test, use our tool to display a pure black screen in a dark room. Turn your monitor's brightness up to maximum and look at the edges and corners of the display. Backlight bleed appears as cloudy patches of light leaking from the frame. This monitor test is especially useful for LCD and LED panels, helping you determine if the display uniformity is acceptable or defective.

IPS glow is a normal characteristic of IPS (In-Plane Switching) panels, appearing as a hazy, glowing effect in the corners of dark screens. Unlike backlight bleeding, which remains static regardless of your position, an IPS glow test reveals that the glow shifts in intensity and location as you change your viewing angle. While you cannot completely remove it, adjusting ambient lighting and lowering screen brightness can reduce its visibility during a display test.

Checking your monitor involves running a comprehensive display test suite. Start with a dead pixel test using solid colors, then proceed to a contrast and gamma test to ensure proper calibration. Follow up with a backlight bleed test in a dark environment and a color banding test to check gradient smoothness. Our complete screen test online platform provides all these diagnostic tools in one convenient place to thoroughly evaluate your panel.

A proper screen test should utilize the primary RGB colors (red, green, blue), along with pure white and pure black. Red, green, and blue screens help isolate stuck subpixels, while a white screen is excellent for checking display uniformity and dust under the glass. A black screen is essential for identifying dead pixels, backlight bleeding, and performing an OLED burn in test to detect image retention.

Yes, you can easily test your laptop screen online using our browser-based screen test tool. The process is identical to testing a desktop monitor. Simply open the tool in your preferred web browser, maximize the window, and run through the various diagnostic screens. This is a quick and effective way to ensure your laptop's display is free from defects, whether it's brand new or you suspect a hardware issue.

Absolutely. Our screen test online platform is fully responsive and works seamlessly on mobile browsers. You can use it to perform a dead pixel test or check display uniformity on your smartphone or tablet. Since many modern phones use OLED technology, our tool is also perfect for running an OLED burn in test to check for UI element retention, such as keyboard or status bar ghosting.

To perform an OLED burn in test, display solid, uniform colors—particularly 5%, 10%, and 50% gray screens, as well as pure magenta or red. Inspect the screen for faint, ghostly outlines of static elements that are frequently displayed, such as taskbars, channel logos, or in-game HUDs. Our screen test tool includes specific gray uniformity slides designed to reveal image retention and permanent burn-in on OLED panels.

Color banding occurs when a display cannot render smooth transitions between shades of color, resulting in distinct, blocky bands instead of a seamless gradient. To detect it, use our color banding test which displays high-resolution gradients. If you see harsh vertical or circular lines rather than a smooth fade, your monitor may have a low color depth (like 6-bit), or you may need to adjust your graphics card settings to output 10-bit color.

Display uniformity refers to a monitor's ability to maintain consistent brightness and color accuracy across the entire screen area. Poor uniformity might manifest as darker corners, uneven color temperatures (e.g., one side looking warmer than the other), or patchy brightness. Using a white screen or gray screen in our display test allows you to visually assess whether the panel suffers from "dirty screen effect" (DSE) or other uniformity issues.

Yes, our screen test tool is completely safe for all types of displays, including LCD, LED, OLED, and CRT. The tool simply displays specific HTML and CSS colors within your browser. It does not overdrive your hardware or access your system files. Even the flashing stuck pixel test is safe for the monitor, though users with photosensitive epilepsy should avoid using the rapid flashing repair feature.

No. ScreenTestTool operates entirely locally within your web browser. We do not require any camera access, nor do we upload screenshots, screen data, or any personal information to our servers. Your monitor test is private and secure, relying solely on client-side rendering to generate the test patterns and colors directly on your device.

Yes, our online display test is compatible with all modern web browsers, including Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge. For the most accurate screen test online, we recommend updating your browser to the latest version and ensuring any color-altering extensions (like night mode or blue light filters) are disabled before running the diagnostics.

ScreenTestTool is 100% free to use. We provide a professional-grade display diagnostics hub without paywalls, subscriptions, or intrusive advertisements. Our goal is to offer the best screen test tool available online, helping users calibrate their monitors, check for dead pixels, and evaluate display quality quickly and easily, without any hidden costs.

No software installation is required. Our monitor test is a purely web-based application. This means you can run a comprehensive dead pixel test, backlight bleed test, or color banding test on any device instantly, without cluttering your system with downloaded executables or apps. Just open the URL, go fullscreen, and begin testing.

Running a screen test immediately after purchasing a new monitor is crucial because many retailers have strict, time-sensitive return policies for display defects. A quick display test helps you spot manufacturing flaws like dead pixels, severe backlight bleed, or poor display uniformity before the return window closes, ensuring you get a flawless panel for your money.

It is a good practice to run a screen test online every few months, or anytime you notice a degradation in image quality. Regular monitor tests help you catch emerging issues early, such as developing stuck pixels or gradual OLED burn-in. If you frequently use your screen for color-critical work like photo editing, regular calibration and uniformity checks are essential.